Mark Pushner

Hi,

I'm working on an 8" RMH design. I have an existing exterior 6" stainless chimney with a 20' height that I would like to use.

My RMH design has about 35-40 feet of bench run, then would exit up the 6" exterior chimney 20' or so to the roof peak.

With the significant cooling that takes place in the 30-40 bench run (and the shrinkage of the air), is this a possibility?

Has anyone ever tried and 8" RMH tied to an existing narrower exterior chimney on a long run?

I suppose I could hook it all up and test it, but prefer anyone feedback if anyone has tried this.

Thanks much,

MP

Is it me or is your duct system going "down hill"? Flat is ok, and anything up is more ideal, down, not so good.

MP

Jonny,

I'm not sure I understand your "extra air" slots and where they are located. If your are drawing air in somewhere else other than the top of the feed tube, then smoke might escape there. Note on an 8" system, a 14" barrel with the bung hole open is enough air to keep these burning ok. That hole is not large at all.

Also why a 10 pipe? Does it have any height outside? How much?

A chimney that is too big diameter and too short will create little draft. A little gust of wind may be all that is needed to create blow back out your feed tube.

MP

Hi,

Planning my first rocket stove. My layout may require up to 40 feet of 8" bench pipe and it will then exit vertical up an 8" chimney about 35 feet. Are these pushing the max lengths of run? I'm using a 55 gal drum on a 8" system like in Onato's book.

Also, my bench layout requires several 90 and 45 degree bends. Again, is there a limit here?

I will have at least 4 - 22.5 to 45 degree and at least 3 90's in the bench. I know it is advised to not have more than 2 90 in a normal wood burner.

Lastly, has anyone ever tied their rocket pipe into an existing wood burner stove pipe? If so how did you make the connection?

I have an existing wood burner and was thinking if I could just do a 45 degree Y into the existing pipe, I could still use both if necessary.

This would then require some type of tightly sealed dampers or "valves" to close any flow from one or the other.

Anyone do such a thing with success?

Lastly, I will bench test this out doors, however I will not be putting up 35' of vertical pipe. How will my stove characteristics change with the long vertical chimney pipe?

Thanks much,

M